Question

Two trains for Palwal leave Kanpur at 10 a.m and 10:30 am and travel at the speeds of 60 kmph and 75 kmph respectively. After how many kilometers from Kanpur will the two trains be together?

Answer 1

Let the train that travels at 60 kmph be train 1

Let the train that travels at 75 kmph be train 2

Find the distance Train 1 traveled  by 1030 am

10am to 10.30am = 1/2 hour

1 hour = 60 km

1/2 hour = 1/2 x 60 = 30 km

Define x:

Let the time be x hour

Calculate the time traveled on the road after 10.30pm:

Train 1:

Time = x

Speed = 60 km/h

Distance = Speed x Time

Distance 60x

*This distance is without the 30km traveled from 10am to 10.30am

Train 2:

Time = x

Speed = 75 km/h

Distance = Speed x Time

Distance = 75x

Solve x:

The time is the same.

60x + 30 = 75x

15x = 30

x = 2

Find the distance:

Distance = 75x = 75(2) = 150 km

Answer: The two train will be together after 150 km from Kanpur